Realistically if you want more grip you wouldn't slam a car on the bump stops. In launches, you want the car to be able to squat down to put more weight onto the back wheels. Same with cornering, when you take a corner the load transfers to the wheels requiring the most grip. If there's no suspension travel, there's no way for the car to get an equal load onto the wheels so it's more prone to spin out. Doubt any of these games go into depth like that though…﻿